61657431 has 8 divisors (see below), whose sum is σ = 89683584. Its totient is φ = 37368120.

The previous prime is 61657423. The next prime is 61657483. The reversal of 61657431 is 13475616.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 61657431 - 2³ = 61657423 is a prime.

It is a super-2 number, since 2×61657431² = 7603277595039522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 1868407 = 61657431 / (6 + 1 + 6 + 5 + 7 + 4 + 3 + 1).

It is a junction number, because it is equal to n+sod(n) for n = 61657392 and 61657401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61657231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 934171 + ... + 934236.

It is an arithmetic number, because the mean of its divisors is an integer number (11210448).

Almost surely, 2^61657431 is an apocalyptic number.

61657431 is a deficient number, since it is larger than the sum of its proper divisors (28026153).

61657431 is a wasteful number, since it uses less digits than its factorization.

61657431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1868421.

The product of its digits is 15120, while the sum is 33.

The square root of 61657431 is about 7852.2245892486. The cubic root of 61657431 is about 395.0588621355.

It can be divided in two parts, 616574 and 31, that added together give a triangular number (616605 = T₁₁₁₀).

The spelling of 61657431 in words is "sixty-one million, six hundred fifty-seven thousand, four hundred thirty-one".